With the development of the display market, consumers have higher requirement on visual effects, including not only various kinds of appearance of a display screen, but also a higher screen-to-body ratio. As a result, the full-screen technologies have been developed and the developing trend is to design a display device with an ultra-narrow bezel or even with no bezel, in order to obtain a screen-to-body ratio equal to or greater than 90%. Such design maximizes a display area without changing a total area of a display device, thereby providing improved visual effects.
However, the narrower a bezel of the display screen is, the worse the sealing property of the display screen will be. Thus, the display screen has a worse performance in preventing moisture from permeating into it. When performing reliability test on such display screen, the moisture might permeate into the display screen easily, causing wires inside the display screen to be exposed into the moisture and thus corroded, thereby resulting in defects.